Living Donor Liver Transplantation in the United States: Evolution of Frequency, Outcomes, Center Volumes, and Factors Associated With Outcomes

Recent Advances in Liver Transplantation for Hepatocellular Carcinoma

OPINION STATEMENT

Liver transplantation for hepatocellular carcinoma (HCC) remains an evolving field. Major challenges HCC transplant patients face today include liver organ donor shortages and the need for both better pre-transplant bridging/downstaging therapies and post-transplant HCC recurrence treatment options. The advent of immunotherapy and the demonstrated efficacy of immune checkpoint inhibitors in multiple solid tumors including advanced/unresectable HCC hold promise in expanding both the neoadjuvant and adjuvant HCC transplant treatment regimen, though caution is needed with these immune modulating agents leading up to and following transplant. New options for pre-transplant HCC management will expand access to this curative option as well as ensure patients have adequate control of their HCC prior to transplant to maximize the utility of a liver donor. Machine perfusion has been an active area of investigation in recent years and could expand the organ donor pool, helping address current liver donor shortages. Finally, additional HCC biomarkers such as AFP-L3 and DCP have shown promise in improving risk stratification of HCC patients. Together, these three recent advancements will likely alter HCC transplant guidelines in the coming years.

The Impact of Donor Body Mass Index on Safety and Outcomes in Living Donor Liver Transplantation: An Analysis of the National United States Database

Background

The prevalence of obesity is rising in the general population. Donor obesity (body mass index ≥30 kg/m2) may potentially reduce the donor pool and impact outcomes in living donor liver transplantation (LDLT).

Methods

We utilized the national transplant database to investigate the impact of donor obesity on donor and recipient outcomes. This was a retrospective cohort study of all LDLTs performed in the United States between January 2010 and June 2023. Outcomes of interest were analyzed by univariable and multivariable logistic regression. Patient and graft survival was evaluated using Kaplan-Meier and Cox proportional analysis.

Results

Six hundred seventy-four donors with obesity and 3498 donors without obesity were analyzed. Donors with obesity had higher rates of readmission within 1 y of donation (15.9% versus 11.6%; P = 0.003). The risk of readmission was significantly different between 6 wk and 6 mo of donation (8.8% versus 5.9%; P = 0.036). Donor body mass index (odds ratio [OR], 1.460; 95% confidence interval [CI], 1.129-1.999; P = 0.004) and preoperative alkaline phosphatase levels (OR, 1.005; 95% CI, 1.000-1.011; P = 0.038) were independent predictors of donor readmission. High LDLT center volume was associated with reduced odds of donor readmission (OR, 0.509; 95% CI, 0.373-0.694; P < 0.001). Graft and recipient survival was comparable.

Conclusions

Selection of living donors with obesity may be a potential avenue to increase the available donor pool without compromising recipient outcomes; however, they are at an increased risk for readmission between 6 wk and 6 mo of donation. The reason for readmission requires further study.

The aim of donor safety: surgical approaches and current results

Living liver donation (LLD) has been suggested as a potential solution to reduce the waitlist mortality for liver transplantation (LT) recipients by facilitating living donor liver transplantation (LDLT). Ensuring both donor and recipient safety is a critical aspect of LDLT. An accurate understanding of the complexity and extend of safety outcomes of the donor is imperative to maintain the high-quality standard this medical program requires. This review seeks to outline safety outcome parameters of interest for donors. Early postoperative mortality is very low with no significant differences comparing left lobe to right lobe LLD. Complications most commonly are biliary (leakage or strictures), bleeding, respiratory or pulmonary, gastrointestinal or infectious. Return to full-time work and quality of life are essential parameters in the mid and long term. As evidence continues to accumulate, outcomes may evolve with the expansion of minimal invasive surgery practice and currently laparoscopic approach is recommended in large experienced centers. By offering safer operations that require fewer incisions or liver resections, living liver donations can be further encouraged, and the perception of the procedure can be improved. Rational consideration of the safety of the donor and in-depth discussion and evaluation with the patient is of utmost importance.

Neighborhood-level social determinants of health measures independently predict receipt of living donor liver transplantation in the United States

Disparities exist in the access to living donor liver transplantation (LDLT) in the United States. However, the association of neighborhood-level social determinants of health (SDoH) on the receipt of LDLT is not well-established. This was a retrospective cohort study of adult liver transplant recipients between January 1, 2005 and December 31, 2021 at centers performing LDLT using the United Network for Organ Sharing database, which was linked through patients' ZIP code to a set of 24 neighborhood-level SDoH measures from different data sources. Temporal trends and center differences in neighborhood Social Deprivation Index (SDI), a validated scale of socioeconomic deprivation ranging from 0 to 100 (0=least disadvantaged), were assessed by transplant type. Multivariable logistic regression evaluated the association of increasing SDI on receipt of LDLT [vs. deceased donor liver transplantation (DDLT)]. There were 51,721 DDLT and 4026 LDLT recipients at 59 LDLT-performing centers during the study period. Of the 24 neighborhood-level SDoH measures studied, the SDI was most different between the 2 transplant types, with LDLT recipients having lower SDI (ie, less socioeconomic disadvantage) than DDLT recipients (median SDI 37 vs. 47; p < 0.001). The median difference in SDI between the LDLT and DDLT groups significantly decreased from 13 in 2005 to 3 in 2021 ( p = 0.003). In the final model, the SDI quintile was independently associated with transplant type ( p < 0.001) with a threshold SDI of ~40, above which increasing SDI was significantly associated with reduced odds of LDLT (vs. reference SDI 1-20). As a neighborhood-level SDoH measure, SDI is useful for evaluating disparities in the context of LDLT. Center outreach efforts that aim to reduce disparities in LDLT could preferentially target US ZIP codes with SDI > 40.

An updated analysis of retransplantation following living donor liver transplantation in the United States: Insights from the latest UNOS database

There is no recent update on the clinical course of retransplantation (re-LT) after living donor liver transplantation (LDLT) in the US using recent national data. The UNOS database (2002-2023) was used to explore patient characteristics in initial LT, comparing deceased donor liver transplantation (DDLT) and LDLT for graft survival (GS), reasons for graft failure, and GS after re-LT. It assesses waitlist dropout and re-LT likelihood, categorizing re-LT cohort based on time to re-listing as acute or chronic (≤ or > 1 mo). Of 132,323 DDLT and 5955 LDLT initial transplants, 3848 DDLT and 302 LDLT recipients underwent re-LT. Of the 302 re-LT following LDLT, 156 were acute and 146 chronic. Primary nonfunction (PNF) was more common in DDLT, although the difference was not statistically significant (17.4% vs. 14.8% for LDLT; p = 0.52). Vascular complications were significantly higher in LDLT (12.5% vs. 8.3% for DDLT; p < 0.01). Acute re-LT showed a larger difference in primary nonfunction between DDLT and LDLT (49.7% vs. 32.0%; p < 0.01). Status 1 patients were more common in DDLT (51.3% vs. 34.0% in LDLT; p < 0.01). In the acute cohort, Kaplan-Meier curves indicated superior GS after re-LT for initial LDLT recipients in both short-term and long-term ( p = 0.02 and < 0.01, respectively), with no significant difference in the chronic cohort. No significant differences in waitlist dropout were observed, but the initial LDLT group had a higher re-LT likelihood in the acute cohort (sHR 1.40, p < 0.01). A sensitivity analysis focusing on the most recent 10-year cohort revealed trends consistent with the overall study findings. LDLT recipients had better GS in re-LT than DDLT. Despite a higher severity of illness, the DDLT cohort was less likely to undergo re-LT.

Survival after live donor versus deceased donor liver transplantation: propensity score-matched study

BACKGROUND

For individuals with advanced liver disease, equipoise in outcomes between live donor liver transplant (LDLT) and deceased donor liver transplant (DDLT) is uncertain.

METHODS

A retrospective cohort study was performed using data extracted from the Scientific Registry of Transplant Recipients. Adults who underwent first-time DDLT or LTDL in the United States between 2002 and 2020 were paired using propensity-score matching with 1:10 ratio without replacement. Patient and graft survival were compared using the model for end-stage liver disease (MELD) score for stratification.

RESULTS

After propensity-score matching, 31 522 DDLT and 3854 LDLT recipients were included. For recipients with MELD scores ≤15, LDLT was associated with superior patient survival (HR = 0.92; 95% c.i. 0.76 to 0.96; P = 0.013). No significant differences in patient survival were observed for MELD scores between 16 and 30. Conversely, for patients with MELD scores >30, LDLT was associated with higher mortality (HR 2.57; 95% c.i. 1.35 to 4.62; P = 0.003). Graft survival was comparable between the two groups for MELD ≤15 and for MELD between 21 and 30. However, for MELD between 16 and 20 (HR = 1.15; 95% c.i. 1.00 to 1.33; P = 0.04) and MELD > 30 (HR = 2.85; 95% c.i. 1.65 to 4.91; P = 0.001), graft survival was considerably shorter after LDLT. Regardless of MELD scores, re-transplantation rate within the first year was significantly higher after LDLT.

CONCLUSIONS

In this large propensity score-matched study using national data, comparable patient survival was found between LDLT and DDLT in recipients with MELD scores between 16 and 30. Conversely, for patients with MELD > 30, LDLT was associated with worse outcomes. These findings underscore the importance of transplant selection for patients with high MELD scores.

Impact of thoracic shape on the surgical outcomes of laparoscopic-assisted living donor hepatectomy

Background

Although laparoscopic-assisted donor hepatectomy (LADH) has become the definitive procedure for harvesting living donor livers, its surgical outcomes in association with donor body shape have not been elucidated.

Methods

The impact of donor factors, including thoracic shape, on LADH outcomes was retrospectively investigated. Thoracic anthropometric data were examined in all LADHs with a left/right graft between 2013 and 2022.

Results

The study included 210 LADHs, consisting of 106 left- and 104 right-lobe donors with similar blood loss and similar operation time. Males have greater thoracic depth and greater thoracic width compared with females, respectively. Thoracic depth was associated with graft weight (p < 0.001), blood loss (p < 0.001), and operation time (p < 0.001). On multivariate analyses, blood loss >500 mL and operation time >8 h were associated with graft weight in the left-lobe donors, and blood loss >500 mL was associated with thoracic depth in the right-lobe donors.

Conclusion

The greater thoracic depth is associated with massive blood loss in right-lobe donors. Anthropometric parameters might be helpful for estimating LADH outcomes.

Early Graft Failure After Living-Donor Liver Transplant

BACKGROUND

Living-donor liver transplantation (LDLT) has been increasing in the USA. While data exist on longer-term patient and graft outcomes, a contemporary analysis of short-term outcomes is needed.

AIM

Evaluate short-term (30-day) graft failure rates and identify predictors associated with these outcomes.

METHODS

Adult (≥ 18) LDLT recipients from 01/2004 to 12/2021 were analyzed from the United States Scientific Registry of Transplant Recipients. Graft status at 30 days was assessed with graft failure defined as retransplantation or death. Comparison of continuous and categorical variables was performed and a multivariable logistic regression was used to identify risk factors of early graft failure.

RESULTS

During the study period, 4544 LDLTs were performed with a graft failure rate of 3.4% (155) at 30 days. Grafts from male donors (aOR: 0.63, CI 0.44-0.89), right lobe grafts (aOR: 0.40, CI 0.27-0.61), recipients aged > 60 years (aOR: 0.52, CI 0.32-0.86), and higher recipient albumin (aOR: 0.73, CI 0.57-0.93) were associated with superior early graft outcomes, whereas Asian recipient race (vs. White; aOR: 3.75, CI 1.98-7.10) and a history of recipient PVT (aOR: 2.7, CI 1.52-4.78) were associated with inferior outcomes. LDLTs performed during the most recent 2016-2021 period (compared to 2004-2009 and 2010-2015) resulted in significantly superior outcomes (aOR: 0.45, p < 0.001).

CONCLUSION

Our study demonstrates that while short-term adult LDLT graft failure is uncommon, there are opportunities for optimizing outcomes by prioritizing right lobe donation, improving candidate nutritional status, and careful pre-transplant risk assessment of candidates with known PVT. Notably, a period effect exists whereby increased LDLT experience in the most recent era correlated with improved outcomes.

Liver transplantation for intrahepatic cholangiocarcinoma: who, when and how

PURPOSE OF REVIEW

Using transplant oncology principles, selected patients with intrahepatic cholangiocarcinoma (iCCA) may achieve long-term survival after liver transplantation. Strategies for identifying and managing these patients are discussed in this review.

RECENT FINDINGS

Unlike initial reports, several modern series have reported positive outcomes after liver transplantation for iCCA. The main challenges are in identifying the appropriate candidates and graft scarcity. Tumor burden and response to neoadjuvant therapies have been successfully used to identify favorable biology in unresectable cases. New molecular biomarkers will probably predict this response in the future. Also, new technologies and better strategies have been used to increase graft availability for these patients without affecting the liver waitlist.

SUMMARY

Liver transplantation for the management of patients with unresectable iCCA is currently a reality under strict research protocols. Who is a candidate for transplantation, when to use neoadjuvant and locoregional therapies, and how to increase graft availability are the main topics of this review.

Approach to Liver Transplantation: Is There a Difference between East and West?

Liver transplantation (LT) remains the only curative treatment for end-stage liver disease as well as acute liver failure. With the exponential increase in organ demand due to the increasing incidence and prevalence of liver diseases, the need to overcome the supply and demand mismatch has arisen. In this review, we discuss the current universal status of LT, emphasizing various LT practices worldwide.

Living Donor Liver Transplantation for Adults With High Model for End-stage Liver Disease Score: The US Experience

BACKGROUND

Outcomes after living-donor liver transplantation (LDLT) at high Model for End-stage Liver Disease (MELD) scores are not well characterized in the United States.

METHODS

This was a retrospective cohort study using Organ Procurement and Transplantation Network data in adults listed for their first liver transplant alone between 2002 and 2021. Cox proportional hazards models evaluated the association of MELD score (<20, 20-24, 25-29, and ≥30) and patient/graft survival after LDLT and the association of donor type (living versus deceased) on outcomes stratified by MELD.

RESULTS

There were 4495 LDLTs included with 5.9% at MELD 25-29 and 1.9% at MELD ≥30. LDLTs at MELD 25-29 and ≥30 LDLT have substantially increased since 2010 and 2015, respectively. Patient survival at MELD ≥30 was not different versus MELD <20: adjusted hazard ratio 1.67 (95% confidence interval, 0.96-2.88). However, graft survival was worse: adjusted hazard ratio (aHR) 1.69 (95% confidence interval, 1.07-2.68). Compared with deceased-donor liver transplant, LDLT led to superior patient survival at MELD <20 (aHR 0.92; P = 0.024) and 20-24 (aHR 0.70; P < 0.001), equivalent patient survival at MELD 25-29 (aHR 0.97; P = 0.843), but worse graft survival at MELD ≥30 (aHR 1.68, P = 0.009).

CONCLUSIONS

Although patient survival remains acceptable, the benefits of LDLT may be lost at MELD ≥30.

Increasing practice and acceptable outcomes of high-MELD living donor liver transplantation in the USA

Recent deceased-donor allocation changes in the United States may have increased high-Model for End-Stage Liver Disease (MELD) living donor liver transplantation (LDLT); however, outcomes in these patients remain poorly defined. We aimed to examine the impact of the MELD score on LDLT outcomes. Using UNOS data (January 1, 2010-December 31, 2021), LDLT recipients were identified and stratified into low-MELD (<15), intermediate-MELD (15-24), and high-MELD (≥25) groups. We compared outcomes between MELD-stratified LDLT groups and between MELD-stratified LDLT and donation after brain death liver transplantation recipients. We used Kaplan-Meier analysis to compare graft survival rates and multivariable Cox proportional hazards modeling to identify factors associated with graft outcomes. Of 3558 LDLTs, 1605 (45.1%) were low-MELD, 1616 (45.4%) intermediate-MELD, and 337 (9.5%) high-MELD. Over the study period, the annual number of LDLTs increased from 282 to 569, and the proportion of high-MELD LDLTs increased from 3.9% to 7.7%. Graft survival was significantly higher in low-MELD versus high-MELD LDLT recipients (adjusted HR = 1.36, 95% CI: 1.03-1.79); however, 5-year survival exceeded 70.0% in both groups. We observed no significant difference in graft survival between high-MELD LDLT and high-MELD donation after brain death liver transplantation recipients (adjusted HR: 1.25, 95% CI:0.99-1.58), with a 5-year survival of 71.5% and 77.3%, respectively. Low LDLT center volume (<3 LDLTs/year) and recipient life support requirement were both associated with inferior graft outcomes among high-MELD LDLT recipients. While higher MELD scores confer graft failure risk in LDLT, high-MELD LDLT outcomes are acceptable with similar outcomes to MELD-stratified donation after brain death liver transplantation recipients. Future practice guidance should consider the expansion of LDLT recommendations to high-MELD recipients in centers with expertise to help reduce donor shortage.

An international survey of venous thromboembolic events and current practices of peri-operative VTE prophylaxis after living donor hepatectomy

BACKGROUND

Venous thromboembolic complications are an uncommon but significant cause of morbidity & mortality after live donor hepatectomy . The precise incidence of these events and the current practices of centers performing living donor liver transplantation worldwide are unknown.

METHODS

An online survey was shared amongst living donor liver transplantation centers containing questions regarding center activity, center protocols for donor screening, peri-operative thromboembolic prophylaxis and an audit of -perioperative venous thromboembolic events after live donor hepatectomy in the previous five years (2016-2020).

RESULTS

Fifty-one centers from twenty countries completed the survey. These centers had cumulatively performed 11500 living donor liver transplants between 2016-2020. All centers included pre-operative l assessment for thromboembolic risk amongst potential liver donors in their protocols. Testing for inherited prothrombotic conditions was performed by 58% of centers. Dual-mode prophylaxis was the most common practice (65%), while eight and four centers used single mode or no routine prophylaxis respectively. Twenty (39%) and 15 (29%) centers reported atleast one perioperative deep venous thrmobosis or pulmonary embolism event respectively. There was one donor mortality directly related to post-operative pulmonary embolism. Overall incidence of deep venous thrombosis and pulmonary embolism events was 3.65 and 1.74 per 1000 live donor hepatectomies respectively. Significant variations in center practices and incidence of thromboembolic events was identified in the survey primarily divided along world regions. 75% of participating centers agreed on the need for clear international guidelines.

CONCLUSION

Venous thromboembolic events after live donor hepatectomy are an uncommon but important cause of donor morbidity. There is significant variation in practice among centers. Evidence-based guidelines regarding risk assessment, and peri-operative prophylaxis are needed.

Selective hanging maneuver and rubber band retraction technique for pure laparoscopic donor right hepatectomy

BACKGROUND

Pure laparoscopic donor hepatectomy (PLDH) is an increasingly performed procedure despite its technical difficulties. This study introduced a selective liver parenchymal hanging maneuver and rubber band retraction technique for PLDH.

METHODS

We retrospectively reviewed perioperative data from 58 patients who underwent donor right hepatectomy (including right extended) between March 2009 and February 2021. Eighteen patients underwent open donor right hepatectomy (ODRH) and 38 patients underwent pure laparoscopic donor right hepatectomy (PLDRH).

RESULTS

All PLDRH donors underwent the procedure without the need for open conversion. The median PLDRH operative time was 396.84 ± 72.459 min, the median PLDRH intraoperative bleeding amount was 496.05 ± 272.591 ml, and the warm ischemic time was 8.77 ± 3.062 min. Compared to ODRH, laparoscopic surgery showed further advantages in terms of postoperative hospital stay (10.94 ± 4.036 days vs. 8.03 ± 2.646 days, respectively, P = 0.01) and estimated blood loss (676.67 ± 321.046 ml vs. 496.05 ± 272.591 ml, respectively, P = 0.033).

CONCLUSIONS

The selective liver parenchymal hanging maneuver and rubber band retraction technique is a simple and effective pure laparoscopic procedure for donor hepatectomy. Our results demonstrate the safety and feasibility of this technique.

Racial Equity in Living Donor Kidney Transplant Centers, 2008-2018

Importance

It is unclear whether center-level factors are associated with racial equity in living donor kidney transplant (LDKT).

Objective

To evaluate center-level factors and racial equity in LDKT during an 11-year time period.

Design, Setting, and Participants

A retrospective cohort longitudinal study was completed in February 2023, of US transplant centers with at least 12 annual LDKTs from January 1, 2008, to December 31, 2018, identified in the Health Resources Services Administration database and linked to the US Renal Data System and the Scientific Registry of Transplant Recipients.

Main Outcomes and Measures

Observed and model-based estimated Black-White mean LDKT rate ratios (RRs), where an RR of 1 indicates racial equity and values less than 1 indicate a lower rate of LDKT of Black patients compared with White patients. Estimated yearly best-case center-specific LDKT RRs between Black and White individuals, where modifiable center characteristics were set to values that would facilitate access to LDKT.

Results

The final cohorts of patients included 394 625 waitlisted adults, of whom 33.1% were Black and 66.9% were White, and 57 222 adult LDKT recipients, of whom 14.1% were Black and 85.9% were White. Among 89 transplant centers, estimated yearly center-level RRs between Black and White individuals accounting for center and population characteristics ranged from 0.0557 in 2008 to 0.771 in 2018. The yearly median RRs ranged from 0.216 in 2016 to 0.285 in 2010. Model-based estimations for the hypothetical best-case scenario resulted in little change in the minimum RR (from 0.0557 to 0.0549), but a greater positive shift in the maximum RR from 0.771 to 0.895. Relative to the observed 582 LDKT in Black patients and 3837 in White patients, the 2018 hypothetical model estimated an increase of 423 (a 72.7% increase) LDKTs for Black patients and of 1838 (a 47.9% increase) LDKTs for White patients.

Conclusions and Relevance

In this cohort study of patients with kidney failure, no substantial improvement occurred over time either in the observed or the covariate-adjusted estimated RRs. Under the best-case hypothetical estimations, modifying centers' participation in the paired exchange and voucher programs and increased access to public insurance may contribute to improved racial equity in LDKT. Additional work is needed to identify center-level and program-specific strategies to improve racial equity in access to LDKT.

Hepatocellular Carcinoma from a Hepatologist's Perspective

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, represents a growing health challenge worldwide. The incidence of HCC is rising, which, in turn, has led to a corresponding increase in the associated number of deaths. HCC will become the third leading cause of cancer-related deaths in the United States by 2030. HCC usually develops in the setting of chronic liver disease. Individuals at increased risk of HCC are recommended to undergo surveillance with ultrasound every 6 months along with serum α-fetoprotein testing. Computed tomography (CT) and magnetic resonance imaging (MRI) are considered alternatives based on specific patient factors. Lesions suspicious for HCC are recommended to undergo a diagnostic testing, which includes contrast-enhanced multiphase CT or MRI and liver biopsy when findings are indeterminate. The Barcelona Clinic Liver Cancer prognosis and treatment strategy is the most used assessment for patients with HCC ( Fig. 2 ). Curative therapies include resection, liver transplantation, and ablation. Locoregional therapies, such as transarterial chemoembolization and radioembolization, can be used for patients with intermediate-stage HCC. For patients with advanced-stage HCC, systemic therapy is often used. This review aims to provide an overview of HCC from a hepatologist's perspective, including epidemiology, screening, surveillance, diagnosis, and management.

Global liver transplantation: emerging trends and ethical challenges

PURPOSE

Liver transplant (LT) is the only definitive treatment for end-stage liver disease (ESLD). This review aims to explore current global LT practices, with an emphasis on challenges and disparities that limit access to LT in different regions of the world.

METHODS

A detailed analysis was performed of present-day liver transplant practices throughout the world, including the etiology of liver disease, patient access to transplantation, surgical costs, and ongoing ethical concerns.

RESULTS

Annually, only 10% of the patients needing a liver transplant receive an organ. Currently, the USA performs the highest volume of liver transplants worldwide, followed by China and Brazil. In both North America and Europe, nonalcoholic fatty liver disease is becoming the most common indication for LT, compared to hepatitis B and C in most Asian, South American, and African countries. While deceased donor liver transplant remains the most performed type of LT, living donor liver transplant is becoming increasingly popular in some parts of the world where it is often the only option due to a lack of well-developed infrastructure for deceased organ donation. Ethical concerns in liver transplantation fundamentally revolve around the definition of a deceased donor and the exploitation of living donor liver donation systems.

CONCLUSION

Globally, liver transplant practices and outcomes are varied, with differences driven by healthcare policies, inequities in healthcare access, and ethical concerns.

Biliary atresia and liver transplantation in the United States: A contemporary analysis

BACKGROUND

Biliary atresia (BA) remains the number one indication for paediatric liver transplantation (LT) worldwide but is an uncommon indication for older LT recipients. The impact of recent donor allocation changes, pervasive organ shortage and evolving LT practices on the BA LT population is unknown.

METHODS

We identified patients who underwent LT between January 2010 and December 2021 using the UNOS database. We compared clinical outcomes between patients with BA and those with non-BA cholestatic liver disease. Groups were stratified by age, <12 years (allocated via PELD system) and ≥12 years (allocated via MELD system). Waitlist outcomes were compared using competing-risk regression analysis, graft survival rates were compared using Kaplan-Meier time-to-event analysis and Cox proportional hazards modelling provided adjusted estimates.

RESULTS

There were 2754 BA LT waitlist additions and 2206 BA LTs (1937 <12 years [younger], 269 ≥12 years [older]). There were no differences in waitlist mortality between BA and non-BA cholestatic patients. Among BA LT recipients, there were 441 (20.0%) living-donor liver transplantations (LDLT) and 611 (27.7%) split deceased-donor LTs. Five-year graft survival was significantly higher among BA versus non-BA cholestatic patients in the older group (88.3% vs. 79.5%, p < .01) but not younger group (89.3% vs. 89.5%). Among BA LT recipients, improved graft outcomes were associated with LDLT (vs. split LT: HR: 2, 95% CI: 1.03-3.91) and higher transplant volume (volume >100 vs. <40 BA LTs: HR: 3.41, 95% CI: 1.87-6.2).

CONCLUSION

Liver transplant outcomes among BA patients are excellent, with LDLT and higher transplant centre volume associated with optimal graft outcomes.

Characteristics of living liver donors in a national referral hospital in Indonesia: a 13-year experience with living donor liver transplantation

Background

Hepatocellular carcinoma and biliary atresia lead to end-stage liver disease, which requires liver transplantation and is linked to increased mortality. Dr. Cipto Mangunkusumo Hospital is the national referral center in Indonesia and is the only center that routinely performs living donor liver transplantation (LDLT). This study presents the characteristics of living liver donors (LLDs) in Indonesia.

Methods

Using the LDLT registry, we conducted a retrospective analysis of all approved donors from 2010 to 2022. The variables included clinical characteristics of the donors, graft types, and intraoperative and postoperative characteristics.

Results

The LDLT rate has increased from 5.8 to 8.8 procedures/year in the last 8 years. The average age of the 76 LLDs was 31.8 years. They were predominantly female (59%) and lived within a family relationship (90%). Pediatric LDLT was more frequent than adult LDLT (88% vs. 12%, respectively). Most grafts (86%) were obtained by left lateral sectionectomy, with a median ratio of remnant liver volume to total liver volume of 79.5% (range, 47.7%-85.8%) and a mean graft-to-recipient weight ratio of 2.65%±1.21%. The median intensive care unit length of stay (LOS) was 2 days (range, 1-5 days) and the total hospital LOS was 7 days (range, 4-28 days). The complication rate was 23%. No donor mortality was reported.

Conclusions

LDLT in Indonesia has increased over the years. The shortage of donors for adult-to-adult liver transplantation is due to cultural differences and challenges in finding eligible donors. This study aims to explain the eligibility criteria of LLDs and contribute to creating a national policy.

Comparing High- and Low-Model for End-Stage Liver Disease Living-Donor Liver Transplantation to Determine Clinical Efficacy: A Systematic Review and Meta-Analysis (CHALICE Study)

INTRODUCTION

Various studies have demonstrated that low-Model for End-Stage Liver Disease (MELD) living-donor liver transplant (LDLT) recipients have better outcomes with improved patient survival than deceased-donor liver transplantation (DDLT) recipients. LDLT recipients gain the most from being transplanted at MELD <25-30; however, some existing data have outlined that LDLT may provide equivalent outcomes in high-MELD and low-MELD patients, although the term "high" MELD is arbitrarily defined in the literature and various cut-off scores are outlined between 20 and 30, although most commonly, the dividing threshold is 25. The aim of this meta-analysis was to compare LDLT in high-MELD with that in low-MELD recipients to determine patient survival and graft survival, as well as perioperative and postoperative complications.

METHODS

Following PROSPERO registration CRD-42021261501, a systematic database search was conducted for the published literature between 1990 and 2021 and yielded a total of 10 studies with 2183 LT recipients; 490 were HM-LDLT recipients and 1693 were LM-LDLT recipients.

RESULTS

Both groups had comparable mortality at 1, 3 and 5 years post-transplant (5-year HR 1.19; 95% CI 0.79-1.79; p-value 0.40) and graft survival (HR 1.08; 95% CI 0.72, 1.63; p-value 0.71). No differences were observed in the rates of major morbidity, hepatic artery thrombosis, biliary complications, intra-abdominal bleeding, wound infection and rejection; however, the HM-LDLT group had higher risk for pulmonary infection, abdominal fluid collection and prolonged ICU stay.

CONCLUSIONS

The high-MELD LDLT group had similar patient and graft survival and morbidities to the low-MELD LDLT group, despite being at higher risk for pulmonary infection, abdominal fluid collection and prolonged ICU stay. The data, primarily sourced from high-volume Asian centers, underscore the feasibility of living donations for liver allografts in high-MELD patients. Given the rising demand for liver allografts, it is sensible to incorporate these insights into U.S. transplant practices.

Preemptive Venoarterial Extracorporeal Membrane Oxygenation for Liver Transplantation-Judicious Candidate Selection

Portopulmonary hypertension is a relatively common pathologic condition in patients with end-stage liver disease. Traditionally, severe pulmonary hypertension is regarded as a contraindication to liver transplantation (LT) due to a high perioperative mortality rate. Recently, extracorporeal membrane oxygenation (ECMO) has been utilized for intraoperative management of LT. As venoarterial (VA) ECMO may benefit certain high-risk LT patients by reducing the ventricular workload by the equivalent of the programmed flow rate, its usage requires multidisciplinary planning with considerations of the associated complications. We highlighted two cases at our single-center institution as examples of high-risk pulmonary hypertension patients undergoing LT on planned VA ECMO. These patients both survived the intraoperative period; however, they had drastically different postoperative outcomes, generating discussions on the importance of judicious patient selection. Since ECMO has removed the barrier of intraoperative survivability, the patient selection process may need to put weight on the patient's potential for postoperative recovery and rehabilitation. Considerations on LT recipients undergoing preemptive ECMO need to expand from the ability of the patients to withstand the demands of the surgery during the immediate perioperative period to the long-term postoperative recovery course.

Maximizing utility of nondirected living liver donor grafts using machine learning

Objective

There is an unmet need for optimizing hepatic allograft allocation from nondirected living liver donors (ND-LLD).

Materials and method

Using OPTN living donor liver transplant (LDLT) data (1/1/2000-12/31/2019), we identified 6328 LDLTs (4621 right, 644 left, 1063 left-lateral grafts). Random forest survival models were constructed to predict 10-year graft survival for each of the 3 graft types.

Results

Donor-to-recipient body surface area ratio was an important predictor in all 3 models. Other predictors in all 3 models were: malignant diagnosis, medical location at LDLT (inpatient/ICU), and moderate ascites. Biliary atresia was important in left and left-lateral graft models. Re-transplant was important in right graft models. C-index for 10-year graft survival predictions for the 3 models were: 0.70 (left-lateral); 0.63 (left); 0.61 (right). Similar C-indices were found for 1-, 3-, and 5-year graft survivals. Comparison of model predictions to actual 10-year graft survivals demonstrated that the predicted upper quartile survival group in each model had significantly better actual 10-year graft survival compared to the lower quartiles (p<0.005).

Conclusion

When applied in clinical context, our models assist with the identification and stratification of potential recipients for hepatic grafts from ND-LLD based on predicted graft survivals, while accounting for complex donor-recipient interactions. These analyses highlight the unmet need for granular data collection and machine learning modeling to identify potential recipients who have the best predicted transplant outcomes with ND-LLD grafts.

Long-term outcomes of retransplantation after live donor liver transplantation: A Western experience

BACKGROUND

Despite most liver transplants in North America being from deceased donors, the number of living donor liver transplants has increased over the last decade. Although outcomes of liver retransplantation after deceased donor liver transplantation have been widely published, outcomes of retransplant after living donor liver transplant need to be further elucidated.

METHOD

We aimed to compare waitlist outcomes and survival post-retransplant in recipients of initial living or deceased donor grafts. Adult liver recipients relisted at University Health Network between April 2000 and October 2020 were retrospectively identified and grouped according to their initial graft: living donor liver transplants or deceased donor liver transplant. A competing risk multivariable model evaluated the association between graft type at first transplant and outcomes after relisting. Survival after retransplant waitlisting (intention-to-treat) and after retransplant (per protocol) were also assessed. Multivariable Cox regression evaluated the effect of initial graft type on survival after retransplant.

RESULTS

A total of 201 recipients were relisted (living donor liver transplants, n = 67; donor liver transplants, n = 134) and 114 underwent retransplant (living donor liver transplants, n = 48; deceased donor liver transplants, n = 66). The waitlist mortality with an initial living donor liver transplant was not significantly different (hazard ratio = 0.51; 95% confidence interval, 0.23-1.10; P = .08). Both unadjusted and adjusted graft loss risks were similar post-retransplant. The risk-adjusted overall intention-to-treat survival after relisting (hazard ratio = 0.76; 95% confidence interval, 0.44-1.32; P = .30) and per protocol survival after retransplant (hazard ratio:1.51; 95% confidence interval, 0.54-4.19; P = .40) were equivalent in those who initially received a living donor liver transplant.

CONCLUSION

Patients requiring relisting and retransplant after either living donor liver transplants or deceased donor liver transplantation experience similar waitlist and survival outcomes.

Regional and National Trends of Adult Living Donor Liver Transplantation in the United States Over the Last Two Decades

BACKGROUND AND AIMS

Liver organ shortage remains a major health burden in the US, with more patients being waitlisted than the number of liver transplants (LTs) performed. This study investigated US national and regional trends in living donor LT (LDLT) and identified factors associated with recipient survival.

METHODS

We retrospectively analyzed LDLT recipients and donors from the United Network Organ Sharing/Organ Procurement Transplant Network database from 1998 until 2019 for clinical characteristics, demographic differences, and survival rate. National and regional trends in LDLT, recipient outcomes, and predictors of survival were analyzed.

RESULTS

Of the 223,571 candidates listed for an LT, 57.5% received an organ, of which only 4.2% were LDLTs. Annual adult LDLTs first peaked at 412 in 2001 but experienced a significant decline to 168 by 2009. LDLTs then gradually increased to 445 in 2019. Region 2 had the highest LDLT numbers (n=919), while region 1 had the highest proportion (11.1%). Overall, post-LT mortality was 21.4% among LDLT recipients. Post-LDLT survival rates after 1-, 5-, and 10-years were 92%, 87%, and 70%, respectively. Interval analysis (2004-2019) showed that patients undergoing LDLT in recent years had lower mortality than in earlier years (hazard ratio=0.81, 95% confidence interval=0.75-0.88).

CONCLUSIONS

Following a substantial decline after a peak in 2001, the number of adult LDLTs steadily increased from 2011 to 2019. However, LDLTs still constitute the minority of the transplant pool in the US. Life-saving policies to increase the use of LDLTs, particularly in regions of high organ demand, should be implemented.

Trends in indications and outcomes of liver transplantation in Canada: A multicenter retrospective study

The liver transplantation (LT) landscape is continuously evolving. We sought to evaluate trends in indications for LT in Canada and the impact of primary liver disease on post-LT outcomes using a national transplant registry. Adult patients who underwent a primary LT between 2000 and 2018 were retrospectively identified in the Canadian Organ Replacement Registry. Outcomes included post-LT patient and graft survival. A total of 5,722 LTs were identified. The number of LT per year increased from 251 in 2000 to 349 in 2018. The proportion of patients transplanted for HCV decreased from 31.5% in 2000 to 3.4% in 2018. In contrast, the percentage of transplants for HCC increased from 2.3% in 2000 to 32.4% in 2018, and those performed for NASH increased from 0.4% in 2005 to 12.6% in 2018. Year of transplant (per 1 year) was protective for both patient (HR:0.96,95%CI:0.94-0.97; P < 0.001) and graft survival (HR:0.97, 95%CI: 0.96-0.99; P = 0.001). Post-LT outcomes have improved over time in this nationwide analysis spanning 18 years. Moreover, trends in the indications for LT have changed, with HCC becoming the leading etiology. The decrease in the proportion of HCV patients and increase in those with NASH has implications on the evolving management of LT patients.